[Bug] kyuubi report an error "Failed to initialize the embedded ZooKeeper server" during initialization.

[XingChenBigData]

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Describe the bug

Describe

Port 2181 is occupied by the QuorumPeerMain process (ZooKeeper main process), causing kill -9 to fail and kyuubi to report an error "Failed to initialize the embedded ZooKeeper server" during initialization.

Solution:

Linux zombie processes or kernel-mode processes will ignore kill -9, and the parent process must be terminated to completely clear them. (Stop QuorumPeerMain via supervisorctl stop zookeeper)
kyuubi's built-in ZooKeeper depends on port 2181 to start. If it is occupied, the service that depends on it will fail to initialize.

Requirement:

Do you have any other solutions?

Problem reproduction:

sh-5.0# jps
72 QuorumPeerMain
sh-5.0# kill -9 72
sh-5.0# jps
5226 QuorumPeerMain

The root cause of the failure of kill -9
The process may be in a zombie state or kernel state blocking, causing the SIGKILL signal to be ignored.
Typical phenomenon: After forced termination, the process ID changes (such as 72 → 5226), indicating that the child process or new instance of the original process is pulled up

执行命令

/opt/kyuubi/bin/kyuubi restart

报错日志如下：

2025-06-08 10:06:04.601 INFO main org.apache.kyuubi.Utils: Loading Kyuubi properties from /etc/kyuubi/conf/kyuubi-defaults.conf                                                                                                 
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:zookeeper.version=3.4.14-4c25d480e66aadd371de8bd2fd8da255ac140bcf, built on 03/06/2019 16:18 GMT                
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:host.name=hadoop-master1.orb.local                                                                              
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.version=1.8.0_432                                                                                          
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.vendor=Azul Systems, Inc.                                                                                  
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.home=/opt/zulu8.82.0.21-ca-jdk8.0.432-linux_aarch64/jre                                                    
2025-06-08 10:06:04.779 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.class.path=/etc/kyuubi/conf:/opt/kyuubi/web-ui:/opt/kyuubi/jars/jetcd-api-0.7.7.jar:/opt/kyuubi/jars/jersey
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.library.path=/opt/hadoop/lib/native:/usr/java/packages/lib/aarch64:/lib:/usr/lib                           
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.io.tmpdir=/tmp                                                                                             
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:java.compiler=<NA>                                                                                              
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:os.name=Linux                                                                                                   
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:os.arch=aarch64                                                                                                 
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:os.version=6.10.14-linuxkit                                                                                     
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:user.name=root                                                                                                  
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:user.home=/root                                                                                                 
2025-06-08 10:06:04.780 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Server environment:user.dir=/                                                                                                      
2025-06-08 10:06:04.789 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: Created server with tickTime 3000 minSessionTimeout 6000 maxSessionTimeout 60000 datadir /opt/kyuubi/embedded_zookeeper/version-2 s
2025-06-08 10:06:04.789 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: minSessionTimeout set to 6000                                                                                                      
2025-06-08 10:06:04.789 INFO main org.apache.kyuubi.shaded.zookeeper.server.ZooKeeperServer: maxSessionTimeout set to 60000                                                                                                     
2025-06-08 10:06:04.796 INFO main org.apache.kyuubi.shaded.zookeeper.server.NIOServerCnxnFactory: binding to port /172.18.0.4:2181                                                                                              
Exception in thread "main" java.lang.RuntimeException: Failed to initialize the embedded ZooKeeper server, binding to 172.18.0.4:2181                                                                                           
        at org.apache.kyuubi.zookeeper.EmbeddedZookeeper.initialize(EmbeddedZookeeper.scala:71)                                                                                                                                 
        at org.apache.kyuubi.server.KyuubiServer$.$anonfun$startServer$1(KyuubiServer.scala:51)                                                                                                                                 
        at scala.Option.foreach(Option.scala:407)                                                                                                                                                                               
        at org.apache.kyuubi.server.KyuubiServer$.startServer(KyuubiServer.scala:50)                                                                                                                                            
        at org.apache.kyuubi.server.KyuubiServer$.main(KyuubiServer.scala:103)                                                                                                                                                  
        at org.apache.kyuubi.server.KyuubiServer.main(KyuubiServer.scala)                                                                                                                                                       
Caused by: java.net.BindException: Address already in use                                                                                                                                                                       
        at sun.nio.ch.Net.bind0(Native Method)                                                                                                                                                                                  
        at sun.nio.ch.Net.bind(Net.java:461)                                                                                                                                                                                    
        at sun.nio.ch.Net.bind(Net.java:453)                                                                                         
        at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:222)                                                 
        at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:85)                                                          
        at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:78)                                                          
        at org.apache.kyuubi.shaded.zookeeper.server.NIOServerCnxnFactory.configure(NIOServerCnxnFactory.java:90)
        at org.apache.kyuubi.zookeeper.EmbeddedZookeeper.initialize(EmbeddedZookeeper.scala:64)                  
        ... 5 more                                               

Affects Version(s)

1.10.0

Kyuubi Server Log Output

Kyuubi Engine Log Output

Kyuubi Server Configurations

Kyuubi Engine Configurations

Additional context

No response

Are you willing to submit PR?

• Yes. I would be willing to submit a PR with guidance from the Kyuubi community to fix.
• No. I cannot submit a PR at this time.

[github-actions[bot]]

Hello @XingChenBigData,
Thanks for finding the time to report the issue!
We really appreciate the community's efforts to improve Apache Kyuubi.

[pan3793]

This is not a bug but a question, and you should emphasize which part of your description is AI-generated.

kyuubi's built-in ZooKeeper depends on port 2181 to start.

This is true if and only if the external Zookeeper/ETCD is not configured in kyuubi-defaults.conf, then an embedded Zookeeper is launched to simplify the setup complexity for explorers.